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Add comment to highlight the inconsistencies in edge lengths computat…
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…ions.
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@Algiane
Algiane committed May 31, 2024
1 parent f09cee8 commit 5a73683
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Showing 6 changed files with 90 additions and 13 deletions.
25 changes: 14 additions & 11 deletions src/common/inlined_functions_private.h
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Original file line number Diff line number Diff line change
Expand Up @@ -43,11 +43,12 @@
* \param m0 metric at point np0.
* \param m1 metric at point np1.
* \param isedg 1 if the edge is a ridge, 0 otherwise.
* \return length of edge according to the prescribed metric, 0 if fail.
* \return length of a curve edge according to the prescribed metric, 0 if fail.
*
* Compute length of surface edge \f$[np0;np1]\f$ according to the prescribed
* aniso metrics \a m0 and \a m1.
* Compute the curve length of surface edge \f$[np0;np1]\f$ according to the
* prescribed aniso metrics \a m0 and \a m1.
*
* \remark the edge has to be a boundary edge
*/
static inline
double MMG5_lenEdg(MMG5_pMesh mesh,MMG5_int np0,MMG5_int np1,
Expand Down Expand Up @@ -83,7 +84,6 @@ double MMG5_lenEdg(MMG5_pMesh mesh,MMG5_int np0,MMG5_int np1,
n2 = &mesh->xpoint[p0->xp].n2[0];
ps1 = ux*n1[0] + uy*n1[1] + uz*n1[2];
ps2 = ux*n2[0] + uy*n2[1] + uz*n2[2];

if ( fabs(ps2) < fabs(ps1) ) {
n1 = &mesh->xpoint[p0->xp].n2[0];
ps1 = ps2;
Expand Down Expand Up @@ -188,10 +188,12 @@ double MMG5_lenEdg(MMG5_pMesh mesh,MMG5_int np0,MMG5_int np1,
* \param isedg 1 if the edge is a ridge, 0 otherwise.
* \return length of edge according to the prescribed metric, 0 if fail.
*
* Compute length of surface edge \f$[i0;i1]\f$ according to the prescribed
* aniso metric (for special storage of metrics at ridges points). Here the
* length is computed taking into account the curve nature of the surface edge.
* Compute the curve length of surface edge \f$[i0;i1]\f$ according to the
* prescribed aniso metric (for special storage of metrics at ridges
* points). Here the length is computed taking into account the curve nature of
* the surface edge.
*
* \remark the edge has to be a boundary edge
*/
static inline
double MMG5_lenSurfEdg_ani(MMG5_pMesh mesh,MMG5_pSol met,MMG5_int np0,MMG5_int np1,int8_t isedg) {
Expand Down Expand Up @@ -257,9 +259,10 @@ double MMG5_lenSurfEdg_ani(MMG5_pMesh mesh,MMG5_pSol met,MMG5_int np0,MMG5_int n
* \param isedg 1 if the edge is a ridge, 0 otherwise.
* \return length of edge according to the prescribed metric.
*
* Compute length of surface edge \f$[i0;i1]\f$ according to the prescribed
* aniso metric (for classic storage of metrics at ridges points).
* Compute the curve length of surface edge \f$[i0;i1]\f$ according to the
* prescribed aniso metric (for classic storage of metrics at ridges points).
*
* \remark the edge has to be a boundary edge
*/
static inline
double MMG5_lenSurfEdg33_ani(MMG5_pMesh mesh,MMG5_pSol met,
Expand All @@ -282,8 +285,8 @@ double MMG5_lenSurfEdg33_ani(MMG5_pMesh mesh,MMG5_pSol met,
* compatibility with \a lenedg_ani).
* \return length of edge according to the prescribed metric.
*
* Compute length of surface edge \f$[i0;i1]\f$ according to the prescribed iso
* metric.
* Compute the "straight" length of edge \f$[i0;i1]\f$ according to the
* prescribed iso metric.
*
*/
static
Expand Down
4 changes: 4 additions & 0 deletions src/mmg3d/colver_3d.c
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Original file line number Diff line number Diff line change
Expand Up @@ -161,6 +161,10 @@ int MMG5_chkcol_int(MMG5_pMesh mesh,MMG5_pSol met,MMG5_int k,int8_t iface,
/* Rough evaluation of edge length (doesn't take into account if some of
* the modified edges of pt0 are boundaries): for a more precise
* computation, we need to update the edge tags of pt0. */

// Algiane 06/24: to check and fix: If the edge is marked as MG_BDY
// (keeping in mind that this tag is not always consistent), the curve
// length is computed, I don't know if it is wanted.
ll = MMG5_lenedgspl(mesh,met,jj,pt0);
if ( (!ll) || (ll > lon) )//LOPTL too small, we need to put greater than 1.41
return 0;
Expand Down
15 changes: 13 additions & 2 deletions src/mmg3d/inlined_functions_3d_private.h
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Expand Up @@ -89,6 +89,9 @@ inline double MMG5_lenedgCoor_ani(double *ca,double *cb,double *sa,double *sb) {
* Compute length of edge \f$[i0;i1]\f$ according to the prescribed aniso
* metric (for classic storage of metrics at ridges points).
*
* \warning in this function we may erroneously approximate the length of a
* curve boundary edge by the length of the straight edge if the "MG_BDY" tag is
* missing along the edge.
*/
static
inline double MMG5_lenedg33_ani(MMG5_pMesh mesh ,MMG5_pSol met, int ia,
Expand All @@ -102,8 +105,10 @@ inline double MMG5_lenedg33_ani(MMG5_pMesh mesh ,MMG5_pSol met, int ia,

if ( pt->xt && (mesh->xtetra[pt->xt].tag[ia] & MG_BDY)) {
isedg = ( mesh->xtetra[pt->xt].tag[ia] & MG_GEO);
// Computation of the length of a curve edge with 33 aniso metric
return MMG5_lenSurfEdg33_ani(mesh, met, ip1, ip2, isedg);
} else {
// Computation for an internal edge with 33 aniso metric
return MMG5_lenedgCoor_ani(mesh->point[ip1].c,mesh->point[ip2].c,
&met->m[6*ip1],&met->m[6*ip2]);
}
Expand Down Expand Up @@ -150,8 +155,8 @@ inline double MMG5_lenedgspl33_ani(MMG5_pMesh mesh ,MMG5_pSol met, int ia,
* \param pt pointer to the tetra from which we come.
* \return length of edge according to the prescribed metric, 0 if fail.
*
* Compute length of edge \f$[i0;i1]\f$ according to the prescribed aniso
* metric (for special storage of metrics at ridges points).
* Compute length of a straight edge \f$[i0;i1]\f$ according to the prescribed
* aniso metric (for special storage of metrics at ridges points).
*
*/
static
Expand Down Expand Up @@ -196,6 +201,10 @@ inline double MMG5_lenedgspl_ani(MMG5_pMesh mesh ,MMG5_pSol met, int ia,
* Compute length of edge \f$[i0;i1]\f$ according to the prescribed aniso
* metric (for special storage of metrics at ridges points).
*
* \warning in this function we may erroneously approximate the length of a
* curve boundary edge by the length of the straight edge if the "MG_BDY" tag is
* missing along the edge.
*
*/
static
inline double MMG5_lenedg_ani(MMG5_pMesh mesh ,MMG5_pSol met, int ia,
Expand All @@ -209,8 +218,10 @@ inline double MMG5_lenedg_ani(MMG5_pMesh mesh ,MMG5_pSol met, int ia,

if ( pt->xt && (mesh->xtetra[pt->xt].tag[ia] & MG_BDY)) {
isedg = ( mesh->xtetra[pt->xt].tag[ia] & MG_GEO);
// Computation of the length of a curve edge with ridge metric
return MMG5_lenSurfEdg_ani(mesh, met, ip1, ip2, isedg);
} else {
// Computation for an internal edge with ridge metric
return MMG5_lenedgspl_ani(mesh ,met, ia, pt);
}
return 0.0;
Expand Down
32 changes: 32 additions & 0 deletions src/mmg3d/libmmg3d_tools.c
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Original file line number Diff line number Diff line change
Expand Up @@ -57,19 +57,39 @@ void MMG3D_setfunc(MMG5_pMesh mesh,MMG5_pSol met) {
MMG5_caltet = MMG5_caltet_iso;
MMG5_caltri = MMG5_caltri_iso;
MMG3D_doSol = MMG3D_doSol_iso;
// same as MMG5_lenSurfEdg_iso for iso metric. The edge can be boundary or
// intenal but the test relies on the MG_BDY tag that may be missing along
// boundary edges (it doesn't matter in iso mode as we always compute the
// "straight" edge length). It starts from tetra pointer and edge index.
MMG5_lenedg = MMG5_lenedg_iso;
// has to be used to compute "straight" edge length from coordinates
MMG3D_lenedgCoor = MMG5_lenedgCoor_iso;
// Straight edge length (edge is guessed to be a surface edge) from point indices
MMG5_lenSurfEdg = MMG5_lenSurfEdg_iso;
}
else {
MMG5_caltet = MMG5_caltet_ani;
MMG5_caltri = MMG5_caltri_ani;
MMG3D_doSol = MMG3D_doSol_ani;
// lenedg is meant to compute the curve length along boundary edges
// and the straight length for internal edges (from
// tetra pointer and an edge index) but it relies
// on the MG_BDY tag which is not always consistent to detect boundary
// edges. Moreover, it seems that the "straight" length is computed in iso
// mode - the origin and effect of computing curve lengths along boudary
// edges should be investigated...
MMG5_lenedg = MMG5_lenedg_ani;
// lenedgCoor has to be used to compute "straight" edge length from
// coordinates
MMG3D_lenedgCoor = MMG5_lenedgCoor_ani;
// lenSurfEdg can be called only from a boundary edge: curve length for
// aniso metric from point indices
MMG5_lenSurfEdg = MMG5_lenSurfEdg_ani;
}
MMG5_intmet = MMG5_intmet_ani;
// warning the lenedg_ani function we may erroneously approximate the length
// of a curve boundary edge by the length of the straight edge if the
// "MG_BDY" tag is missing along the edge.
MMG5_lenedgspl = MMG5_lenedg_ani;
MMG5_movintpt = MMG5_movintpt_ani;
MMG5_movbdyregpt = MMG5_movbdyregpt_ani;
Expand Down Expand Up @@ -97,8 +117,14 @@ void MMG3D_setfunc(MMG5_pMesh mesh,MMG5_pSol met) {
}
MMG5_caltri = MMG5_caltri_iso;
MMG3D_doSol = MMG3D_doSol_iso;
// same as MMG5_lenSurfEdg_iso for iso metric. The edge can be boundary or
// intenal but the test relies on the MG_BDY tag that may be missing along
// boundary edges (it doesn't matter in iso mode as we always compute the
// "straight" edge length). It starts from tetra pointer and edge index.
MMG5_lenedg = MMG5_lenedg_iso;
// lenedgCoor has to be used to compute "straight" edge length from coordinates
MMG3D_lenedgCoor = MMG5_lenedgCoor_iso;
// Straight edge length (edge is guessed to be a surface edge) from point indices
MMG5_lenSurfEdg = MMG5_lenSurfEdg_iso;
MMG5_intmet = MMG5_intmet_iso;
MMG5_lenedgspl = MMG5_lenedg_iso;
Expand Down Expand Up @@ -1402,9 +1428,15 @@ int MMG3D_searchlen(MMG5_pMesh mesh, MMG5_pSol met, double lmin,
ier = MMG5_hashPop(&hash,np,nq);
if( ier ) {
if ( (!metRidTyp) && met->m && met->size>1 ) {
// Warning: for aniso metrics, we may erroneously approximate the
// length of a curve boundary edge by the length of the straight edge
// if the "MG_BDY" tag is missing along the edge.
len = MMG5_lenedg(mesh,met,ia,pt);
}
else {
// Warning: we may erroneously approximate the length of a curve
// boundary edge by the length of the straight edge if the "MG_BDY"
// tag is missing along the edge.
len = MMG5_lenedg33_ani(mesh,met,ia,pt);
}

Expand Down
6 changes: 6 additions & 0 deletions src/mmg3d/quality_3d.c
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Original file line number Diff line number Diff line change
Expand Up @@ -295,9 +295,15 @@ int MMG3D_computePrilen( MMG5_pMesh mesh, MMG5_pSol met, double* avlen,
ier = MMG5_hashPop(&hash,np,nq);
if( ier ) {
if ( (!metRidTyp) && met->size==6 && met->m ) {
// Warning: we may erroneously approximate the length of a curve
// boundary edge by the length of the straight edge if the "MG_BDY"
// tag is missing along the edge.
len = MMG5_lenedg33_ani(mesh,met,ia,pt);
}
else
// Warning: we may erroneously approximate the length of a curve
// boundary edge by the length of the straight edge if the "MG_BDY"
// tag is missing along the edge.
len = MMG5_lenedg(mesh,met,ia,pt);


Expand Down
21 changes: 21 additions & 0 deletions src/mmg3d/split_3d.c
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Original file line number Diff line number Diff line change
Expand Up @@ -648,8 +648,14 @@ int MMG5_split1b(MMG5_pMesh mesh, MMG5_pSol met,int64_t *list, int ret, MMG5_int
for (i=0; i<6; i++) {
pt = &mesh->tetra[list[j]/6];
if ( (!metRidTyp) && met->m && met->size>1 )
// Warning: we may erroneously approximate the length of a curve
// boundary edge by the length of the straight edge if the "MG_BDY"
// tag is missing along the edge.
len = MMG5_lenedg33_ani(mesh,met,i,pt);
else
// Warning: for aniso metrics we may erroneously approximate the
// length of a curve boundary edge by the length of the straight edge
// if the "MG_BDY" tag is missing along the edge.
len = MMG5_lenedg(mesh,met,i,pt);
if ( len < lmin) {
lmin = len;
Expand Down Expand Up @@ -684,9 +690,17 @@ int MMG5_split1b(MMG5_pMesh mesh, MMG5_pSol met,int64_t *list, int ret, MMG5_int
}
}
if ( (!metRidTyp) && met->m && met->size>1 )
/* Computation of straight edge length */
len = MMG5_lenedgspl33_ani(mesh,met,taued[5],pt0);
else
/* if edge is marked MG_BDY, curve length is computed, if edge is not
* MG_BDY, straight length is computed (even if the edge is indeed along
* the boundary but misses the tag). // Algiane 06/24: to check and fix
* or comment (I don't know if it is useful to compute the accurate
* curve length here)
*/
len = MMG5_lenedgspl(mesh,met,taued[5],pt0);

if ( len < lmin ) break;
memcpy(pt0,pt,sizeof(MMG5_Tetra));

Expand All @@ -698,8 +712,15 @@ int MMG5_split1b(MMG5_pMesh mesh, MMG5_pSol met,int64_t *list, int ret, MMG5_int
}

if ( (!metRidTyp) && met->m && met->size>1 )
/* Computation of straight edge length */
len = MMG5_lenedgspl33_ani(mesh,met,taued[5],pt0);
else
/* if edge is marked MG_BDY, curve length is computed, if edge is not
* MG_BDY, straight length is computed (even if the edge is indeed along
* the boundary but misses the tag). // Algiane 06/24: to check and fix
* or comment (I don't know if it is useful to compute the accurate
* curve length here)
*/
len = MMG5_lenedgspl(mesh,met,taued[5],pt0);
if ( len < lmin ) break;
}
Expand Down

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